Sheet-metal working machine



p 1931- I P. R. HAHNEMANN 1,822,697

SHEET METAL WORKING MACHINE Filed Oct. 4 1929 5 Sheets-Sheet l Sept. 8, 1931. P. R. HAHNEMANN 1,822,697

SHEET METAL WORKING MACHINE I Filed Oct. 4, 1929 3 Sheets-Sheet 2 flfforneys Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE PAUL R. HAHN EMANN, OF BUFFAID, NEW YORK, ASSIGNOR TO NIAGABA'HAOHINE & TOOL WORKS, OF BUFFALO, NEW 'YORK, A CORPORATION OF NEW YORK SHEET-METAL WORKING MACHINE Application filed October 4, 1929. Serial 1W0. 397,405.

adjusting the position of the working rolls lengthwise relative to each other while the machine is at rest or while the same is 1n operation.

A further object of this invention is to 'provide means for adjusting the position of rolls vertically relatively to one another to suit the thickness of the sheet metal which .IlS being operated upon and, also to adapt the same to meet other conditions.

An additional object ofthis invention is to so organize the machine that the rolls may be moved toward one another either by hand power or foot power, or by a comb nation of both, as best suits the requirements of the work in hand.

In the accompanying drawings:-

Figure 1 is a side elevation of a metal working machine embodying said improvements.

Figure 2 is a top plan view of the same.

Figure 3 is a fragmentary vertical longitudinal section, on an enlarged scale taken on line 33 Fig. 4, of the upper part of the machine, showing the working rolls closed and in operative engagement with a sheet of metal which is being worked.

Figures 4 and 5 are vertical transverse sections taken on the correspondingly numbered lines in 3. I

Figure 6 is a fragmentary horizontal section taken on line 66 Fig; 3.

Figure 7 is a fragmentary vertical longitudinal section, similar to Fig. 3, showing the working rolls separated or opened into an inoperative position. r

Figures 8, 9 and 10 are fragmentaryvertical longitudinal sections taken on the-cor-' respondingly numbered lines in Figs. 4 and Figure 11 is a vertical transverse section on. a reduced scale, taken on line 11 11-o Fig. 1, and showing the upper part of the frame with the workin parts omitted.

In the following escription, similar characters of reference indicate like parts in the several figures of the drawings.

The main frame of this machine upon which the working parts are supported preferably comprises a lower base portion or pedestal adapted to rest upon the floor and an upper housing or casing which is mounted on the upper end of the pedestal and preferably comprises a main housing or hollow body section which is secured at its lower end to the upper end of the pedestal, and an overhanging support rojecting forwardly from the upper part of the housing. The housing comprises an upright front Wall 21, an upright rear wall 22, upright side walls 23, 24, and a horizontal top 25. The overhanging support of the housing comprises a lower hollow arm 26 which projects forwardly from the front wall 21- of the body of the housing around the lower part of an openlng 27 formed in the upper front part ,of this housing and an upper hollow arm 28 projecting forwardly from the upper front part of the housing around the upper part of the opening 27 and separated from the lower arm 26 by an intervening horizontal gap 29 which opens forwardly.

The numerals 30 and 31 represent the lower" andupper working rolls of the machine which may have their peripheries constructed of any suitable form for the purpose of heading, turning, cutting or slitting a sheet of metal 32 which is placed between the same by 'lhe operator. As shown-in Figs. 1, 2, 3 and 7, the cooperating surfaces of these rolls are adapted to produce a bead 33in the sheet-metal work-piece 32 by providing the lower roll 30 with an annular groove 34 and the upper roll 31 with an annular rib 35 which projects into the groove 34; so that upon engaging these rolls with the lower and u per side of the sheet 32 a bead 33 will be ormed on the same. Obvi- I that the inner end of this bearing projects sever the same into sections, or to slitparts "thereon in a manner well-known 1n this art The lower roll is me ted on the front end of a horizontal longitudinal shaft 36.

whichis journaled in a tubular bearing 37 preferably formed integrally with the lower supporting arm 26 and pro ecting inwardly from the elevated front end of this, arm so into the upper (part of the housing or body and is separate from the lower end of the gap 27 by an intervening space, as shown in Fig. 3. s

Motion may be imparted to the lower roll 30 and the parts associated therewith from any suitable source,-but in the present case power is derived from the electric motor 38 mounted on the lower rear part of the housing and operatively connected with the rear vend of the lower roll shaft 36 by a speedreducing gearing, which preferably comprises a gear pinion 39 secured to the inner or front end of the motor shaft 40, a gear wheel 41 meshing with the pinion 39 and mounted on an arbor 42 which 'is'carried by the front wall 21 of the housing, a gear pinion 43 connected with the gear wheel 41 and meshing with a gear wheel 44 mounted on an intermediateshaft 45 journaled in suitable bearings on the housing, a ear pinion 46 secured to the intermediate s aft 45 and meshing with agear wheel 47 which turns on a sleeve48- keyed to the rear end of the lower roll shaft 36, and a clutch sleeve 49 keyed to the bearing sleeve 48 and movable lengthwise thereon toward and from aclutch jaw 50 on the rear side of the gear wheeli47 for the purposeof coupling and uncoupling the lower roll shaft 36 with this gear wheel 47.

The clutch sleeve 49 may be moved for coupling and uncoupling the clutch by any suitable means but preferably by the means which are shown in Figs. 1, 2, 3, 4 and 8 and which comprise a horizontal rock shaft 51 journaled transversely in the upper rear part of the frame housing, a forked arm 52 projecting downwardly from the shaft 51 within the housing and provided with shifting rollers 53 engaging with an annular groove 54 in the clutch sleeve 49, means for rocking 60 formed on the fork 52 and having a head 61 at its front end which is seated in a socket 62 in the front wall 21 of the housing and bears against a'plug 63 secured in the front end of the socket 62 and a spring 64 surrounding the guide rod 58 and bearing with its front-end against the head 61 while its,

inner or rear end bears against the front side of the fork extension 60. The rod 58 and the spring 64 may be inserted and removed upon detaching the screw plug 63.

Upon depressing the treadle 55 the clutch sleeve 49' will be moved forwardly into engagement with the clutch jaw or collar 50 of the gear wheel 47 and thereby operatively connecting the motor 38 with the lower working roll 30. Upon releasing the foot pressure on the treadle 55 the spring 64 op- I crates to shift the parts so as to move the clutch sleeve 49 out of engagement with the clutch collar 50 and thereby uncouple the shaft 36 from the motor so that the machine is at rest,

If desired, the clutch may be operated by hand at the top of the machine instead of by foot pressure for which purpose a rock lever is secured to the outer end of the rock shaft 51 and provided on its lower arm 65 with a stop 66 adapted to engage with a stop lug 67 on the adjacent part of the. frame, while its upper arm 68 is provided with a screw 69' adapted to engage a fixed projection 70 on the adjacent part of the frame, and is also provided with an upwardly projecting handle 71 which may be grasped by the op- 1 erator for manipulating the clutch. The lower stop 66 of the hand-operated clutch lever is preferably fixed so as to limit the pressurewhich can be applied to the clutch sleeve 49 when the same engages the clutch collar 50.

-The purpose of the screw 69 is to keep the clutch sleeve 49 in engagement with the driven clutch member '50 so that the machine operates continuously and the foot treadle 55 is rendered inoperative. It is, apparent that upon treading on the treadle 55. the member 65 swings rearwardly around its supporting pin.

Upon then tightening the screw against the stop 70, the parts are held in this position and the clutch held in continuous engagement so that the machine operates continuously and the treadle 55 isentirely inoperative. Upon restoring the parts to their normal position by loosening the screw 69, the foot treadle again controlsrth'e operation of the machine. 7

The upper working roll 31 is mounted on the front end of an' upper longitudinal shaft 72 which is driven in unison with the lower roll shaft 30 by means of intermeshing gear wheels 73, 74 secured, respectively, to the rear parts of these shafts, as shown in Figs. 3, 5 and 7. The upper roll shaft 72 is mountings 89, 90 in the top ed so as to swing vertically and enable the upper roll 31 to move vertically toward and from the lower roll 30 during which movement the driven gear wheel 74 of the upper roll 72 merely moves sidewise to a moderate extent, but always remains in mesh with the driving gearwheel 73 on the lower roll shaft 36. For this purpose the upper roll' shaft 72 /is journale adjacent to its front and rear ends in'bearings 75, 76 formed on the under side of the front and rear ends of a vertically swinging shifting arm or lever 77 which turns about a horizontal transverse axis represented in the present case. by a pin 78 passing through the upper rear part of this arm and mounted on an adjustable support, and associated with adjusting means whereby the upper roll shaft may be moved bodily forwardly or backwardly lengthwise of the lower roll shaft 30 in order to cause the upper roll 31 to occupy a proper position relative to the lower roll for performing the intended operations upon the sheet-metal blank or work-piece.

Means for thus adjusting the shifting arm or lever 77 and the parts mounted thereon lengthwise of the machine, as shown in Figs. 1, 2, 3, 4, 5, 7 9 and are constructed as follows :Astride of the rear part of the shifting lever 77 is a yoke havmg a trans verse cross-bar 79 extending over the lever 77 above the ivot pin 78 and two arms 80 which de en from opposite ends of the cross-bar g9 and support the pivot pin 78 at its opposite ends on opposite sides of the shifting lever 77, as best shownin Fig. 5.

The lower ends of the yoke arms 80 are pivoted on their outer sides on trunnions 81 mounted on the adjacent side walls 23, 24 of the housing, and on the inner lower parts of these yoke arms are formed vertical longitudi'nal guide faces 82 which engage with vertical longitudinal faces 83 on cheeks 84 which roject downwardly from the rear part of the shifting lever 77 on opposite sides of the upper roll shaft 72.

The numerals 85 and 86 represent two upright adjusting screws which pass through threaded openings in the cross bar 79 and hear at their lower ends against the upper surface of this lever in front and in rear of the pivot pin 78 and are provided at their upper ends with knurled heads or thumbpieces 87, 88 which project through openof the housing so that they are accesslble from the exterior of the machine and within convenient reach of the operator for adjusting purposes.

In the position of the arts shown in Fig. 3 the yoke and the shi ing lever 77 connected therewith are in the proper relative position for causing the rib of the upper roll to engage properly with the groove 34: of the lower roll to roduce the bead 33 on the sheet-metal wor -piece. If these rolls should be replaced by others for performing a different 0 eration which would necessitate moving t e upper roll shaft 72 forwardly in order to cause. the two rolls to-cooperate promptly, such forward bodily movement of the upper roll shaft 72 can be efi'ect ed by turning the front screw 85 backwardly and the rear screw 86 forwardly, whereby the angularity of the shifting lever 77 relative to the-yoke is ad'u'sted' so as to throw the upper, roll 31 forwardly, as shown by dotted lines in Fig. 7

.In like manner the upper roll shaft 72 can be moved rearwardl bodil together with the roll associated t erewit by turning the front screw 85 forwardly and backing up on the rear screw 86. By this means the two working rolls can be convenientl andaccurately adjusted relatively to eac other while the machine is in operation to suit the requirements of the particular rolls which are in use.

During this adjustment of the shifting lever 77 relative to the oke, the guide faces 83 on the rear part of the lever slide lengthwise between the guide faces 82 on the arms of the yoke and after such adjustment these cooperating guide faces serve to hold the shifting lever and yoke securely against lateral displacement so that the same practically form an integral structure, whereby the upper roll 31 is maintained in the proper position relative to the lower roll to insure the production of accurate work. I

Means are provided whereby the shifting lever 77 is yleldingly held in its" elevated position and the upper working roll 31 is raised but of cooperating relation to the lower working roll 30 to permit of introducing the sheet metal work piece between these rollers, and also removing the same therefrom. In its preferred construction this lifting device is constructed as follows The numeral 91 representsa tubular socket which projects downwardly through an opening 92 in the top of the upper housing arm 28 and provided with an annular flange 19 at its upper end which rests upon a seat formed on the upper side of this arm around this opening so that this tubular socket is capable of rocking to a limited extent by reason of the swivel joint produced between the socket and the top of the arm 28. Projectin downwardly into this socket is a helica spring 93 which bears against an internal upwardly facing shoulder 94 at the lower end of this socket.

Extending downwardly through this springis a llfting rod 95 which is supported on the upper end of this spring by means of a Washer 96 inter osed between this sprin and screw nuts 9 secured to the threade upper end of this rod. 'The lower part of the latter extends downwardly into an opening 18 in the front part of the shifting lever in an elevated position, the tension of t spring being adjustable by tightening or loosening the screw nuts '97 thereon.

Depression of the upper working roller relative to the lower roller either by hand power or foot power, and also adjustment of the uppermost position of the upper roller relative to the lower roller to su1t different sizes of work which may be performed, is effected by means which embody applicants improvements, and which are constructed as follows The numeral 100 represents a vertically movable gear rack which is preferably inclined rearwardly from its lower end toward its upper end and slides in a guideway 101 on the upper part of the supporting arm 28 of the housing. The teeth 102 on the front side of this gear rack are engaged b the teeth of a rotary gear segment 103 WhlCll is arranged on the inner end of a shaft 104 journaled transversely and horizontally in a bearing 105 on the front part of the overhanging arm 28.

Turning ofthis gear segment for the purpose of lowering the gear rack 100 is effected by means of a treadle 106 pivoted to swing vertically on the lower part of the base and connected by means of a shifting rod 107 with a rock arm 108 projecting rearwardly from one end of the gear segment shaft 105.

Extending downwardly through the gear segment is an adjusting rod 109 which bears at its lower end against a seat 110 on the upper front part of the shifting lever 77 and provided ad acent to its upper end with an external screw-thread 111 which works in a corresponding internal thread in the upper part of the gear rack 100 so that u on turning this adjusting rod by means 0 a crank or handle 112 arranged at the upper end thereof, the adjusting rod can be shifted with reference to the gear rack and thereby, vary the position of the shifting lever 77 with reference to the gear rack. After adjustment the adjusting rod 109 is held in place by clamping nuts 17 In the elevated position of the upper forming roll 31 the rock arm 108 is arranged horizontally or substantially so as indicated by upper dotted position of this arm in Fig. 3 and the horizontal broken line passin through the axis of the same and the pivota connection between the same and the operating rod 107.

Upon depressing the treadle 106 the gear segment 103 is turned in the direction for.

lowering the gear rack 100 and causing the upper roll'31 to move toward the lower roll 30 so as to cause these rolls, to'operate upon the sheet of metal which is passed between the same, and upon releasing the downward pressure on the treadle 106Lthe spring 93 raises the shifting lever77 and the up er roll 31 so as to permit of removing the nished work and enable another piece of work to be introduced between the rolls. a By this means a powerful foot-pressure can be exerted through the medium of the upper roll against the sheet-metal workiece while the latter is being supported on 1ts under side by thedower roll, WhlCh is particularly desirable when workin" on comparatively heavy sheet metal, and it is also advantageous in that it permits the lowering of the upper roll to be effected easily and with less fatigue than if the upper roll were depressed by hand pressure, thereby relievin the operator from considerable manual e fort and enabling him to increase the output of the machine, which is particularly important when engaged in what is known as production work requirin to be her 0 work-pieces.

' It has been found in practice that when working on comparatively heavy sheet metal that a heav downward strain is applied to the forwar 1y projecting lower arm 26 and a heavy upward strain is applied to the upper arm 28 of the frame housing, and that in the absence of any provision which would prevent it, the front wall 21 of the housing is liable to be fractured or give way under such strains. To prevent such occurrence the upper part of the front wall 21 of the spring housing is reinforced by means of heavy reinforcing ribs 113 which extend horizontally across the inner side of this wall at the inner end of the lower arm 26, and connect the boss 114, which supports the front end of the shaft 45, with the adjacent parts of the side walls 23, 24; also by providing strengthening ribs 115 arranged on the inner side of this wall 21 and connecting opposite sides of the bearing 37 with the side walls 23, 24 of the housing; and also by providing a strengthening rib 116 on the inner side ofthe wall 21 so as to con nect the boss 114 with the boss 117, whereby the arbor 42 is supported on the front wall 21; and by also providing a rib 118 on the inner side of he wall 21 so as to connect the boss 117 with the adjacent wall 23, as-

best shown in Figs. 3, 4 and 11.

This reinforcement permits of making the .out liability of fracturing the frame.

When beading very heavy sheet metal or when it is desired to bead a single'piece of the same operation erformed successfully on a large num-' sheet metal for a special purpose, the screwoperated adjustinfg rod 109 can be mampu lated by means 0 the handle 112 for doing this work to the exclusion of the gear mechanism which is pedal-operated. j

In order to permit the adjusting rod 109 to exert downward pressure against the shifting lever 77 for depressing the latter and moving the upper roll 31 into operative .relation with the lower roll 30, the gear rack fromthe lower working roll either by hand or foot power, depending on the character of the work or other conditions.

By inclining the gear rack 100 and the adjusting screw mounted therein rearwardly, the upper part of this mechanism, and particularly the handle 112 of the adjusting rod is carried rearwardly out of the way so as to clear the space immediately in front of the upper part of the machine so as to enable the workmen to manipulate the machine and the work-piece which is being operated upon, without any interference from this adjusting mechanism.

, The positioning of the work-piece upon introducing the same between the working rolls and into the gap 29 between the lower and upper supporting arms 26 and 28 is ef-' fected by placing the same against a gage 119 which extend transversely across the gap 29 in rear of the workingrolls and is supported by one or more adjusting rods 120, each extending longitudinally rearward from the gage and into an opening 121 in the adjacent front part of the frame where it is held in its adjusted position by means of a clamping screw 122.

I claim as my invention 2-- 1. A machine of the character described, comprising a frame, a lower roll shaft journaled on said frame, an upper roll shaft; and means for movably mounting said upper roll shaft relatively to said lower roll shaft including a vertically swinging shifting lever upon which said upper roll shaft is journaled, a yoke which is pivotally connected with said shifting lever and with said frame, and means for adjustingthe angularity of said lever and yoke relatively to one another for shifting the upper roll' shaft bodily lengthwise of said lower roll shaft.

2. A machine of the character described, comprising a frame, a lower roll shaft journaled on said frame, an upper roll shaft; and means for movably mounting said upper roll shaft relatively to said lower roll shaft including a vertically swinging shifting lever upon which said upper roll shaft is ournaled, a yoke pivoted at its upper end to the rear end of said lever and pivoted at its lower end to said frame, and means for adjusting the angularity of said lever and yoke in a direction lengthwise of said shafts.

3. A machine of the character described, comprising a frame, a lower roll shaft journaled on said frame, an upper roll shaft; and means for movablymounting said upper roll shaft relatively to said lower roll shaft including a vertically swinging shifting lever upon which said u per roll shaft is journaled, a yoke pivote at its upper end to the rear end of said lever and pivoted at its lower end to said frame, and means for adjusting the angularity of said lever and yoke in a direction lengthwise of said shafts, consisting of adjusting screws mounted on said yoke and engaging with said lever in front and in rear, respectively, of the pivotal connection between saidlever and yoke.

4. A machine of the character described, comprising a frame, a lower roll shaft journaled on said frame, an upper roll shaft; and means for movably mounting said upper roll shaft relatively to said lower roll shaft including. a vertically swinging shifting lever upon which said upper roll shaft is journaled, a yoke straddling the rear part of said lever and having a cross-bar extending over the top thereof and two arms which slidingly engage opposite sides of said lever, a transverse pivot connecting the upper part of said yoke with the rear part of said lever, transverse pivots connectin the lower parts of said yoke arms with said rame; and adjusting screws mounted on the cross bar of said yoke and engaging with the upper side of said lever in front and in rear of said pivotal connection between said lever and yoke.

5. A machine of the character described,

comprising a frame, a lower roll shaft jour-' naled on said frame, an upper roll shaft; and means for movably mounting said upper roll shaft relatively to said lower roll shaft including a vertically swinging shifting lever upon which said upper roll shaft is journaled, a yoke pivoted at its upper end to the rear end of said lever and pivoted at its lower end to said frame, and means for adjusting the angularity of said lever and yoke in a directionlengthwise of said shafts, consisting of adjusting screws mounted on said yoke and engaging with said lever in front and in rear, respectively, of the pivotal connection between said lever and yoke, said frame being provided in its top with openings through which said ad usting screws project upwardly.

6. A machine of the character described,

comprising a frame, a lowerroll shaft journaled on the frame, an upper roll shaft, ,a vertically swinging shifting lever which 1s mounted on the frame and on which the up 5 per roll shaft is journaled, means for depressing said shlfting lever, and mean s "for holding said shiftin lever yieldlngly 1n an elevated position inc uding a tubular socket rojecting downwardly through an opening in the top of saidframe and provided with an external annular flange resting on top of the franie around said opening and also provided with an internal shoulder, a spring arranged in said socket and resting with its lower end against said shoulder, and a lifting rod passing through said spring and socket and resting at its upper end on, the upper end of said spring while its lower end is connected with said shifting lever.

7. A machine of the character described, comprising a frame, a lower roll shaft journaled on the frame, an upper roll shaft, a vertically swingin shifting lever which is mounted on the. rame and on which the upper roll shaft is journaled, and means for depressing said lever including a gear rack lded on the frame and operatively engagmg said lever, and a gear segment journaled on the frame andmeshing with said rack.

8. A machine of the character described, comprising a frame, a lower roll shaft journaled on the frame, an upper roll-shaft, a vertically swingin shifting lever which is mounted on the rame and on which the upper roll shaft is journaled, and means for depressing said lever includmg a gear rack ided on the frame and operatively engaging said lever, a gear segment journaled on the frame and meshing with said rack, a rock arm connected with said gear segment, and a treadle connected with said rock arm. 9. Axmachine of the character described, comprising a frame, a lower roll shaft journaledfon the frame, an upper roll shaft, a vertically swingin shifting lever which is mounted on the rame and on which the upper roll shaft is journaled, and means for depressing said shifting lever including a gear rack slidably mounted on the frame, a gear segment journaled on the frame and meshing with the gear rack, and an adjusting screw working in said gear rack and engaging the upper side of said shifting lever.

10. A machine of the character described, comprising a frame, a lower roll shaft journaled on-the frame, an upper roll shaft, a vertically swingin shifting lever which is mounted on the rame and on which the .65 an adjusting screw working in said gear upper roll shaft is journaled and means assess? rack and engaging the upper side of said shifting lever, sai screw inclining rearwardly.

11. A machine of the character described,

comprising a frame provided with a hollowbody having a front wall, upper and lower arms projecting forwardl from thefront wall of said body and remforcin ribs arranged on the inner side of said ront wall adjacent to the inner ends of said arms, a

lower working roll mounted on said lower arm and adapted to exert a downward thrust thereagainst, and an upper working roll movably mounted on the upper part of said frame and adapted to exert an upward thrust thereagainst.

12. A machine of the character described, comprising a frame provided with a hollow body having ,a front-wall, an upper arm projecting forwardly from the upper end of said front wall, a lower hollow arm projecting forwardly from a lower part of said wall, a bearing extending from the front end of said lower arm rearwardly into said end of said lower arm rearwardly into said body, and a rib arranged on the inner side of said front wall at the inner end of said lower arm; a lower roll shaft journaled in said bearing; and an upper roll shaft mounted on said body and upper arm.

gear rack and adjusting 14. A machine of the character described, I

comprising a frame provided with a hollow body havlng a front wall, an upper arm pro ecting forwardly from the upper end of said front wall, a lower hollow arm projecting" forwardly from a lower part of said wall, a bearing extending from the front end of said lower arm rearwardly into said body, a rib arranged on the inner side of said front wall at the inner end of said lower arm, bosses arranged on the innerside of said front -wall adjacent to said rib, and

'ribsconnecting said bosses with each other and with the walls of said body; a lower roll shaft journaled in said bearing; and an upper roll shaft mounted on said body and upper arm.

15. A machine of the character described, comprising a frame having a fixed bearing, a lower roll shaft journaled in said bearing, an upper roll shaft movable toward and from said lower shaft; and means for driving said roll shafts including a driven gear wheel rotatable concentrically about said lower roll shaft and provided with a clutch collar, a clutch sleeve adapted to engage said clutch collar and rotatable with said lower shaft but slidable lengthwise relative thereto; and means for shifting said clutch sleeve includin a rock shaft mounted on the frame, an mner rock arm mounted on the rock shaft and engaging said sleeve, an outer rock arm mounted on the rock shaft, and a treadle connected with said outer rock arm.

16. A machine of the character described, comprising a frame having a fixed bearing, a lower roll shaft journaled in said bearing, an upper roll shaft movable toward and from said lower shaft; and means for driving said roll shafts including a driven gear wheel rotatable concentrically about said lower roll shaft and provided with a clutch collar, a clutch sleeve adapted to engage said clutch collar and rotatable with sa1d lower shaft but slidable lengthwise relative thereto; and means for shifting said clutch sleeve including a rock shaft mounted on the frame, an inner rock arm mounted on the rock shaft and engaging said sleeve, an outer rock arm mounted on the rock shaft, a treadle connected with said outer rock arm, a guide rod having its inner end passing through said inner rock arm and provided on its outer end with a head, a sprin interposed bet en said head and inner roc arm, a socket on said frame which receives said head, and a screw plug arranged in said socket and engaging the outer end of said head.

17 A machine of the character described, comprising a frame, upper and lower cooperating rolls, a shaft .carrying one of said rolls, a driving wheel mounted on said shaft and having a clutch collar, a clutch sleeve splined on said shaft and movable toward and from said clutch collar, an inner rock-lever connected with said sleeve, an outer rock lever connected with the inner rock lever, a fixed stop arranged on the frame and adapted to be engaged by said outer lever for limiting the separatlon of said clutch sleeve and collar, a screw arranged on said outer lever and adapted to enga e a fixed sto on the frame, and a trea econnected with said outer rock lever.

In testimony whereof I hereby afiix 'my PAUL R. HAHNEMANN.

" signature. 

